【摘要】 采用Monte Carlo模拟方法对聚丙烯酸/聚环氧乙烷(PAA/PEO)梳型聚合物在固液界面吸附形态进行了模拟,得到了聚合物在液相中的聚集形态及在固液界面上吸附形态的瞬时构型,同时获得了聚合物的吸附层厚度、均方回转半径和吸附在固液界面的各种链段数等微观信息.结果表明,随着聚合物的接枝数(Np)增大,聚合物在液相中的扩散系数逐渐降低、相对黏度逐渐增大;当Np≥6时,羧基阴离子基团位于吸附层最外围,吸附层厚度近似等于PEO侧链长度,聚合物在固体表面形成空间排斥为主,静电排斥为辅的吸附状态;吸附聚合物分子密度过低或过高均不能起到良好的空间屏蔽或阻隔效应;吸附在固体粒子表面的聚合物应具有适宜的吸附-脱附自平衡能力.更多还原

【Abstract】 The conformation of polyacrylic acid/polyethylene oxide(PAA/PEO) comb polymer adsorbed on the solid-liquid interface was investigated via Monte Carlo simulation method.The conformation images in the liquid and on the solid surface of various architecture polymer molecules were obtained.The microstructure information of various architecture polymer molecules,including the mean square radius of gyration,the thickness of adsorbed layer and the number of various segments adsorbed on solid surface were collected.The results showed that the diffusion coefficients in the liquid gradually reduced and the relative viscosity gradually rose with the polymer grafting number(Np) increasing.When Np≥6,the most carboxyl anion groups of comb polymer were placed outside of the adsorbed layer and the thickness of adsorbed layer approximated the length of the PEO side chains,the conformation of a comb polymer molecule on solid surface mainly played a steric barrier effect and secondly electrostatic repulsive.Meanwhile the polymer molecule should have suitable density of steric scattering and could keep self balance of adsorbing-desorbing.更多还原